Lifting jack



2 Sheets-Sheet l Oct. A19, 1937. M, 5 LUCKER LIFTING JACK Filed June 25,1954 M. B. LucKER Oct. 19, 1937.

LIFTING JACK 2 Sheets--Sheecl 2 Filed June 25, 1954 Patented' Oct. 19,1,937

LIFTING JACK Millard B. Lucker, Benton Harbor, Mich., assignor to AutoSpecialties Mfg. Co.,

St. Joseph, Mich.,

a corporation of California Application June 25, 1934, Serial No.732,197

14 Claims.

This invention relates to lifting jacks of the screw type, and moreparticularly to the several lifting parts and to improved methods forproducing them and assembling them into position.

It is an object of the invention to providel an economical and readilyoperable method for form ing the lifting parts of a liftingY jack andfor assembling them into operative relation and position.

It is a further object of the invention to provide a method for forminga` thread stop on a screw of a lifting jack which may be readily carriedout by a cold forging operation, no drilling or fitting of parts beingrequired.

It is a further object of the invention to provide a thread stop on ascrew which is. positive in action, which is strong and durable, whichwill not jam or lock, and which has no projections tending to cut orscratch the surface with which u the screw engages.

1t is a further object of the invention to provide in a lifting jackmeans for securing a lifting screw to its operating gearin non-separablerelation merely by the inter-fitting of the parts without 1 heading overor deforming them during assembly,

but separation of the parts being readily permitted by a predeterminedmanipulation of them.

It is a further object to produce an attachment lug on a lifting screwby a single cold forging operation, the lug which is produced beinguniform and rugged so as not to be easily broken.

Other objects and advantages of the invention will appear from thefollowing description. taken in connection with the accompanyingdrawings,

ssiwherein certain preferred embodiments of the inlifting screws inextended condition.

Fig. 3 is a sectional View through the assembly of Fig. l taken on theline 3-3 thereof.

Fig. l is a perspective view of the inner solid lifting screw` whichembodies certain features of the invention.

Figs. 5, 6, and '7 are Views of the die blocks used for forming theattachment lug at the lower end of the screw.

Figs. 8, 9, 10, 11, and 12 are views showing the several steps ofassemblngthe jack parts.

Figs. 13, 14, and 15 are views showing the deformed thread stop at theupper end of the inner screw.

Figs. 16 and 1'7 are views of the die blocks used for producing adeformed thread stop, and

Fig. 18 is aplan View of the screw driving gear showing moreparticularly the opening in the center of the gear through which theattachment lug on the screw extends.

While the invention is shown for purposesof illustration applied to anextensible lifting jack of the type commonly used for raising automotivevehicles, it is to be understood that the invention is equallyapplicable to other types of screw jacks or equivalent devices.

In Figs. l and 2 there is shown an extensible bottom drive lifting jackof the general type disclosed in my prior patent, Reissue Patent No.17,527, dated December 17, 1929; As shown, av generally cylindricalelongated casting l0 hasV formed in the bottom portion thereof a bearingfor receiving a rotatable shaft ll towhich there is secured at the innerend and within the casting, a driving pinion i2. To the other end of theshaft ll there is secured a member having Ya squared socket lll adaptedto receive a suitable handle by which the shaft and the pinion l2 may berotated to extend the jack. Secured to the bottom of the casting li in asuitable manner is a base cap member It, upon which there is-supported arotatable gear Viii in engagement with and vadapted to be rotated bypinion l2. The gear i8 is centered with respect to cap member l@ bymeans of an upstanding circular ridge i9 formed on the cap member whichengages the under side Aof the bevelled flange of the gear, as shownparticularly in Fig. 1.

The inner or small solid screw 2l of the jack is carried upon the gearIB and is secured there. to and constrained for rotation therewith bymeans of an attachment lug consisting of a generally rectangular oroblong extension 23, extending axially from theV lower end thereofthrough a similarlyv shaped opening, best shown in Fig. 18, formed inthe central part of the gear, and a projection 24', formed angularly atthe end of the extension. The attachment lug co-operates with pinion I2andan inwardly struck projection 2B formed iny casting member l0 to holdscrew 2l and the gear I8 in non-separable relation, as will be moreparticularly pointed out hereinafter. Screw 2| is threaded throughoutits length, the threads at the upper end of the screw being deformed toform a thread stop. Y

The threads of screw 2 l engage threads formed In forming thejattachmentlug, Athe threaded therewith. In the instance .shown a.taper pinZSarranged between the'threads is used; The external thread on thescrewsleeve 28 Vco-operi- -ates with the thread forned internally on theinternally onr thelower upset orY thickened end of anintermediatelscrew'sleeve 28. The screwsleevev 28 is threaded'externally throughoutits length, the external threads at the upper end of the sleeve havingsome suitable thread stop arranged lower upset or thickened end on anouter or large threadedsleeve member 38. YAt theV upper end Vofsleeve3llA is secured a cap 3| which is adapted to engage the object tobe lifted by'mega-ek;VV The cap memberl may besuitablysecured to sleeve30Yby heading over a'flange on thecap intov I an annular. recess 32 cutin :the 'upper end of"V sleeve 30. Sleeve 304 is notextern-allythreaded,

Y Y casting l0, to prevent withdrawal but has at its lower extremity aradially extending' projection 34 which'slides withinY an elongatedrchannel 35 running substantially throughout the length of anon-threadedrsleeve member 31, which embraces'sleeve 30; Channel 35 isstruck inwardly'at its upper end, as indicated at 38, Fig. 2, Vtoprevent'the withdrawal of vprojection'34 upwardly Afrom the channel.VChan- Y nel 35f`ts within andfslides longitudinally offa co-operatingchannel Y 40, Vformed longitudinally substantially throughout the lengthof AcastingY member l0. Channel 35 is formedawith Yan out-.V wardlystruck portion 4I at its lower end 'which Y co-'operates with aninwardly projecting portion 42 Aformed at the upper endrofV the channel48 in Wardly from casting l0. Y 1

The Vpresent inventionV relatesV particularly Vto gear I8 and screws 27|and128,`and tothe method for forming andsecuring these parts.4

Screwr2| maybe VformedrfromY a piece of cyf .lindric-al metalbar stockcut to desired length,V

and threaded throughout its entire length. j The attachment lug formedat the lower jend ofthe screw, and theVV several deformedthreads Aform-V-ing a thread'stopat its upper end are Well shownV in Fig.Y 4, aperspectiverview of the entire screw. f f The dieblocks for forming theattachment lug 1 Vthe means of -attachment of the screw to the gear Ythe blocks taken-substantially on the line-55 ,ofV

-Fig. ,6. Lower Ydie block 42 has running from oneV Y, endV thereofasemifcylindrical groove` 43v terrni' hating in a verticalwall portion 44in the planerV Y of the stepped up portion .42 of the die blockp' ahorizontal face portion 45, an angular portion I8 are shownY infFigs. 5,6, and?. "Fig."1.i`s a perspective view vof.` the lower die block v'42.'Fig. 6 is a longitudinal section Ythrough both dieV blocks, VandFig. 5is a transverse section through 46, and a second vertical wall portion41. VVDie Vfaces 45,546 and 41gareV bounded laterally by a pair ofvertical walls 48, forming'a continuation Vofthe semiecylindrical groove43. 'Y Y .Upperdie'blo'ck 5B has a semi-cylindricalgroove' Y `5l runningthe length thereof Vadapted tomate' with groove 43and lower die block42,' a steppedf up portion co-operating with Ylowerndie steppedY Vupportion 42', andgardepending projection 52 Ywhich isy adaptedV to extenddownwardly between screw is placed s with its lower' end abutting theverticalwall41: Vof the lower die block. The dies are then broughttogether forming theentire attachment lug by the vertical side g-wallsV48 Voffthe lower die block*VV towardbut not in contactwilth yhorizontal-rrdie facef45.V

between the separatedV die'blocks Y ence toY Figs. 13 to 177, inclusive.are views taken from the side and top, respectiveof sleeve V31 ups ofand substantially at :right at the lower end of Athe screw whichYconstitutes i screw threads.` n j vformed. The topV portions threadsbeing too wide to co-operate with the vinsingle operation. 'This.operation is exceedingly simple', only one operation ofjthe dies beingrequired,A and. by the Yoperation a uniform and subv stantial lug isformed. The forging operation maybe performed'without heating themetaland,l

accordingly; thereis no; danger of destroying its tensilev strength byoverheating.

The means for forming the threadst'opat the Y upperend. of the screw isbest described by refer;

l'y, of Figi` .of the upper deformed *threadY portion of 4the screw,Fig. 13 is a View similar to Fig. 15

,but showing the. deformedv or mutilated screw thread inrranintermediate process of formation, and Figs. liand 1'1are views of thedie-blocks Y f forforming the deformed threads.

f The upper'ahd lower die blocks 54 are in this instancesimilar, eachhaving'a longitudinally ex 'Y tending semi-cylindrical groove 56 runningfrom one VVend substantially the length thereof and terminating near theother one end ofthe block Figs. 14 Yand 15 in a vertical wall portion'51 inthe plane ofV a.'

vertically kstepped downportion 55 formed in"V the face of the` die.'portions 55, the faces willV be separated, as shown Yin Fig. 16, whenthe die blocks are broughttogether.. i

In forming the deformed or mutilated threads,

Due to the stepped down 4*the threaded screw 2| isplaced betweenitheseparated die blocks with its upper end in line with the 58 ofthe twodie blocks end. faces 59 of the'blocks. TheY dies are theni f.

brought together, which forms on theY screw a pair of substantially'flatinwardly struck parallel; 'Y

walls 68 on the' end of theV screw,y as shown in Fig. 14, theV distance`between Vthe WallsV being thatV 58 ofthe dies whenthe dies Y are inclosed or operated position. The threads,v

between the faces will be mashed substantially smooth Von the faces-After the initial forgingoperation the dies areV separated Aand theescrew Vis fromV the end faces body lies Wholly within thelongitudinal'grooves 53.Y During thisY withdrawal rotated throughdegrees. VThe Vdies areY then brought togethera second time.

formed threads of thefscrew Which were struckV Y During `this forgingoperation the top 'portions l2rof the .de-j

Y alongv the faces 58 of the die. yblock so thatthe threads remaining on'the ends;

pulled rearwardly f 590i Vthe die blocks until its j 'of the screwit isv55 outwardly along thefaces 58Vof the'die during' the firstforgingoperation areY againy flattened e .into their originalsemi-cylindrical contour being.'

thereby thickened; V-The `bottom portions V62 ofV these threads,however,.aresubstantially undisl n turbed during this operation. Thefinal screw threads formed therefore,are asshown in Fig. 15, havingtheir top portions 62 Ywidened. butlying 62'V struck outwardly withrespect to porrespond-- ing bottom screwV portions -A double "threadstop is thus 62 vof the deformed ternal thread on sleeve28, and thebottomlfthrea'd portions 62 of the deformed threads being struck 63 ofthe u'ndeformedf` in the plane ofthe top portions 63 of the uncle-fVVformed 'screwY threads, and their bottom portions outwardly from theaxis of the screw so that they will likewise not co-operate with theinternal thread of sleeve 28.

This method of forming a thread stop is exceedingly simple and may bevery readily carried out. Only one pair of dies is required and theoperation is therefore substantially a single one, although two diemovements are necessary. The operation may be carried out withoutheating so that' the tensile strength of the screw is not destroyed, andthere is no machining, drilling, or fitting of separable parts.

Sleeve 28 may be formed by upsetting or thickening its lower end portionin any suitable manner, after which the internal threads are cut on thethickened portion and the external threads are cut throughout the lengthof the sleeve. After the threads are cut, the outer threads at the topof the sleever are fitted with a'suitable thread stop. As indicated inFigs. 1 and 2, in this instance a tapered pin 29 fitted into the wall ofthe sleeve and arranged between the threads is used but other equivalentstop means could be provided; or the threads at the upper end of screwsleeve 28 could be deformed to form the thread stop as in the case withscrew 2|, similar forging dies of larger size being used, and thesequence of operations being the same. However, if the threads were sodeformed a center piece of hard metal should be inserted into the sleeveto preserve its interior cylindrical surface during the thread forgingoperations, so that screw 2| could fit within the upper end of thesleeve so as not to sacrifice any of the lifting range of the jack.

'I'he manner of assembling the several parts of the jack is bestunderstood by reference tol Figs. 8 to l2, inclusive. The inner or smallsolid screw 2| threaded throughout its length and having its upper endthreads deformed to form the thread stop, as shown in Fig. 8, is firstthreaded downwardly through the sleeve 28, as shown in Fig. 9, thesleeve 28 being in completed form, having both its inner and outerthreads thereon and its upper end being arranged with the thread stop.At the time screw not as yet been forged to form the attachment lug, aswill be seen by reference to Fig. 9. This is essential for during theformation of parts 23 and 24 at the lower end of screw 2| by the forgingoperation thereon, the threads at the lower end of the screw aremutilated so that they could not thereafter be threaded through sleeve28.

After screw 2| is threaded through sleeve 28 the attachment lugconsisting of extension 23 and projection 24 is forged on the lower endof the inner screw, as previously described, and thereafter sleeve 28carrying the screw 2| may be threaded downwardly through outer largethreaded sleeve 30, as indicated in Fig. 10. Non-threaded sleeve 31 maythen be dropped into position over sleeve 30, as indicated in Fig. 11,after which cap 3| may be secured to sleeve 38.

Gear I8 is now assembled on the lower end of screw 2|, as indicated inFig. l1, by rst moving it to the dotted position shown, and thereaftermoving it to the position shown in full lines. It will be noted that theangular face 46 of lower die 'block 42, forms an angular portion 24',Figs. 4

and l1, on the projection 24 which allows for the movement of gear I8 toassembled position. Casting I8 is now dropped over the assembly, asshown in Fig. 12, and cap I6 is brought up from below and secured tocasting I0, as shown in Figs. 1 and 2, to form the completed jack. Itwill be noted by 2| is threaded through screw sleeve 28, the lower endof the screw 2| hasV reference to Figs. 1 and 11 that removal of gear I8from screw 2| is impossible unless the gear is moved angularly withrespect to axis of the screw member 2| to its angular dotted lineposition of Fig. 11. In the completely assembled jack such relativeangular movement of gear I8 is prevented by the pinion I2 and theinwardly struck projection 26 of castingV of the gear at diametricallyopposite points and hold it in position. The casting and the severalsleeves hold the screw 2| upright, thus positively preventing anyrelatively angular movement between gear |8 and 2|, even though anupward force is applied to screw 2|, as by the turning of the jackupside-downorV otherwise. Accidental separation of gear I8 and screw 2|is thereby positively prevented, however, these parts may bereadilyseparated for repair and replacement, and the like, merely by theremoval of cap member I6 and a reversal of the assembly operationpreviously described.

It will be seen that the means for assembling parts I8 and 2| isextremely simple, no heading over or hammering of extension 23 beingrequired'after the gear is placed in position with respect to the screw.The projection-24 being formed by a forging operation, may be madesubstantial and is thus. definitely superior to a projection of variableand doubtful size or strength which might be put on the end of extension23 manually with a hammer or the like, during the assembling of theparts.

In operation pinion I2 is rotated to'effect the extension of the jack.The operation of pinion I2 rotates gear I8 meshing therewith, andoperation of gear I8 rotates screw 2|. Sleeve 30.v is held from rotationby virtue of the engagement of its extension 34 with channel 35 insleeve 3'I, and by virtue of the engagement of this channel 35 with thelarger channel 48 formed in casting IIJ. Screw 2| is in threadedengagement with sleeve 28, and sleeve 28 is in turnin threadedengagement with sleeve 30. As screw 2| is rotated therefore, and sleeve30 held from rotation, it will be seen that, due to the threadedengagement of the parts, sleeves 28 and 38 will be extended from screw2| from the Fig. 1 to the Fig. 2 position of the parts. During thisoperation sleeve 28 may at times rotate with screw 2l and at times beheld non-rotatable with sleeve 30. Ultimately, however, the parts willreach their Fig. 2 position.

The mutilated or deformed threads at the upper end of screw 2| and thestop 29 on sleeve 28 limit the upward movement of the parts. Due to thefact that the thread deformations or mutilations on screw 2| are sharplyformed, the mutilated portions have no tendency to wedge or jam withtheir co-operating threads. The thread stop which is thus formed by thethread mutilation is strong and is positive in action inasmuch as adouble stop is formed, one stop being the widened top 62 of themutilated threads,.and the other stop being the outwardly extendingbottom portion 82' of the threads. There is no danger that the deformedportions will be sheared off in use, nor is there any chance that theywill come loose. During the second forging operation between dies 54,the top portions B2 of the mutilated threads are positively formed intotheir original semi-cylindrical contour, and hence they have no tendencyto scratch or mutilate the sleeve surfaces with which they co-operate.During operation and regardless of the position to which the jack ismoved, gear I8 and I8 whichengage the top f screw 2l are held innon-separable relation; howinthe constructions and steps of formationandV rever, these parts may be readily separated for Y.

repair, replacement cover'lrG. Y e .Y Y ,c e Y Itis obvious that variouschanges may be made orY the like, upon removal of assembly whichfIhaveset out for purposes of l thread stop.

formedoutwardly from'the axis of the screw illustration. My invention,`however, contemplates'the use of equivalentswthroughout, and I thereforeVdo VYnotwish to be limited to the pre- Vcise constructions and methodand assembly steps the following claims. Y

AIclaim: YY' Y 'Y 1. V'In a lifting jack, a-Y cylindrical screw,-and aScrew'thread cut therein, the groove portion of the screw thread beingdeformed .outwardly from the axis of the screw sho-wn .and described,but only asirindicated in V2..A screw comprising a screw body, and ahelical thread cut therein, said thread having its top portionVwidenedand its groove portion deat one point to form a threadfstop. Y eY3.*In a.V liftingjack, a lifting screw body, a screwrthrea'd cutsubstantially along the'length of saidY body and formed at one end withamutilated portion, said mutilated portion comprising a widened threadtop and a 'shallow thread `groove,and a lifting screw sleeve havingthreaded engagement with 'said first-,mentioned thread.

4. In a lifting jack, a lifting screw formed at one end .with anraxialextension having a pro'-,

l jection thereon having a symmetric lateralY extension Yfrom the screwaxis, and an operating` gear for a liftingV screw having .an opening Ythrough which the extension projects.

5. In a combination with a gear and ashaft operable therewith, meansforsecuring the shaft to the gear comprising a hook-like extension on saidshaft. adapted to'rextendy axially and laterally from theV shaft throughan-opening in the gear, and means for holdingsaid gear, from movementangularlywithrespect to the axisV of the shaft.

` 6. Ina combination with a gear and a shaft' l"operable therewith,means for securing the shaft tothe gear comprising Va hook-likeextension on ,"said shaft adapted to. extend axially and laterally fromthe shaftthrough an opening in` the gear, means for Vholding saidVgear;,from movement angularly with Y'respectfto'the axis of thediametrically opposed relation. Y Y

, 17. VIn a lifting jack,a supporta gear; rotatablyV carriedY by saidVsupport; a lifting screw carried Eby said gear and hield upright by saidsupport, Vand means for securing the screw to the ,gearfor ro- Vtationtherewith comprising a hook-like exten- "sion on the screw adaptedto'project through an opening formed in thegear, a projectiononsaidsupportengaging'the upper gear face, and a drivingpi'nion for the gearalso engaging theupper 'face thereof and held in position bythefsupport,

said projection and said driving pinion'being sub- YYstantially.diametrically arranged with'respect to Ysaidgear.- `Y Y '7.Y

at one pointY to form a 8, In a lifting jack,a driving gear, aliftingscrew, means for'Y securing the-lifting screwV to the driving gear forrotation therewith comprising a hook-like Yextension formedonsaidscrewprojectingthrough` an opening in said gearand meansrfor preventingrelative movementbetween said gear and screw,v a thread formed onY Ymeans for preventing relative movement between Vsaidrgea'r and saidscrew, the threadof said screw prevent axial sepabeingmutilated at oneendto ration of said screw and said sleeve.V

at Ythe top andfdecreasing in depth to provide Aa stop.` Y Y Y Y10. m' alifting jaaa-jin combination with .al housing including a basal portionupon which the.

` said screw, athreadedV sleeve threadedly embrac- Y "ing said screw,said sleeve formingipartg'of the 9. A iifungf jack 'havingarotatabiygdriven member and ajthreaded liftingelement, aportion off thethread of said element being widened jack is adapted to rest,'a gearfreely' restingjon the upper surface of AtheYbase, a threaded drivingelement having a freely detachable connection f with said gear andlenclosed in said housing, 'said Y connection being'positioned inoperative relationship by said housing. i Y L l '11. In 1a lifting jack,inV combination Vwith a lifting housing having a base, a driving pinionin saidhousing, a .driving gear freely resting on the bottom of Asaidbase and meshing with. the teeth of the Ypinion, a driving threadedelement having a freely detachable connection with said Y gearandenclosed by said housing,jsaid housing forming means for preventing thedetachment of saidjdeta'chable connection when said jack-is inYoperation, Y ,Y y

12. In a liftingjack, the combination of a housing, a plurality ofthreaded lifting screws in Ysaid housing adapted for relative actualmove-"Y ment, means for'operating said screwsincluding a gear and meansfor non-separably securingone of said screws to the gear said Ascrew by.said gear upon rotation of v'said gear and merely by the intertting of aVpartv Aof said screwto said gear without heading or del forming saidscrew or gear during assembly,Y said means permitting separationof saidscrew from said gear by aV predetermined manipulation of lllel'ffl.V Y rref j y 13. In a lifting jack,rthe' combination of a ing said gear, aplurality ofY relatively movable to permit operation of Y Y Y F50housing, a gear `m said housing, means for rotat- Y inter-threadedmembers, one fof Asaid1threaded. l

members havingY Y with-said gear :including means for causing Yrotationof said Y,threaded member by said gear in the normal Ioperation ofthejack, said housing including Vmeans for preventingVV detachment of' saidthreaded member from 'said gear during the Ynormal operation of thejack. Y y

14h-In'Y a lifting jack construction, a'drivingV gear, aA liftingscrew,Y said gear being rotatable a freely detachable.,connectionV Yrz55 about the Yaxis of the screw'and valso-being bodily e displaceablewith respect to the screw axis, means forming aconnection between thegear detachable Yupon Ybodily displacement of the gear with'respect tothescrew axis,Y and means forA holdingthe gear from such bodilydisplacement MILLARD B. LCKER :'65 and screw whereby said screw 1srotatably driven Y n as the gear is rotated,said'connection-beingfreelyras the gear and screw are normally mounted in 70 Y the jackconstruction.

